Swiss pharmaceutical group Roche has asked generic drug firms to help speed up the manufacture of a key anti-viral ahead of a feared bird flu pandemic.

Demand has soared for the drug Tamiflu, which can fight the H5N1 avian flu strain causing concern at the moment.

"We will have much more Tamiflu available than if Roche produced it itself," said New York Senator Charles Schumer after talks with Roche.

The firms Teva, Barr, Mylan and Ranbaxy aim to start production within a month.

'In a timely manner'

"Roche has agreed to meet with these companies as soon as possible, as early as next week, and to meet with additional companies which might also be interested in making Tamiflu," said Mr Schumer after his meeting with George Abercrombie, head of Roche's US operations.

Roche is keen to ensure the generic drug firms are able to produce sufficient quantities of Tamiflu before they grant them a license to do so.

"We want to be sure that they can produce substantial amounts of Tamiflu for pandemic use in a timely manner in accordance with appropriate quality specifications, safety and regulatory guidelines," the company said.

Demand for the drug is by far outstripping supply, even though Roche has doubled production every year for three years.

By next summer, the company will have boosted its output eightfold when compared with 2004.

Forty governments have placed massive orders to protect their populations in case the bird flu virus mutates into a form where it poses a serious threat to human health.